Field effect transistor and method for producing the field effect transistor

摘要

In a field effect transistor including a Schottky gate electrode (30) disposed on an active region (2) formed in a compound semiconductor substrate (1), a compressive stress of the gate electrode (30) and a tensile stress of an insulating film (8) serving as a passivation are concentrated on the lower end part of the gate electrode (30), whereby positive piezoelectric charges are produced in the compound semiconductor substrate (1) in the vicinity of the gate electrode (30). The positive piezoelectric charges increase the effective donor concentration, reducing the thickness of the surface depletion layer. As the result, the channel narrowing due to the surface depletion layer is suppressed.